Fix tier badging

Update tier badge to indicate self-managed.

doc/integration/auth0.md

@@ -4,7 +4,7 @@ group: Ecosystem
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
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-# Auth0 OmniAuth Provider **(FREE)**
+# Auth0 OmniAuth Provider **(FREE SELF)**
 
 To enable the Auth0 OmniAuth provider, you must create an Auth0 account, and an
 application.